This invention relates to a lightweight, low cost sprayable ablator composition.
Ablative materials heretofore used as heat shields in space vehicles adapted for being subjected to high velocity, high temperature conditions during re-entry into the earth's atmosphere have been fabricated either in the form of sheets or blocks of material, which must be conformed to the shape of the surface being covered and adhered thereto.
A disadvantage of such systems is the difficulty of removing the ablative material, e.g., sheets of cork, from the space vehicle after re-entry, owing to the adhesion of pieces thereof to the surface of the vehicle.
Another disadvantage of known ablator materials and systems is the difficulty encountered in fashioning a uniform covering, presenting a smooth surface to the atmosphere during flight and re-entry.
A further disadvantage of known systems is the great expenditure of time required to fabricate a covering piece-by piece on the outside of the space vehicle. Thus-fabricated coverings usually require lengthy cure cycles for production of an even, adherent ablative covering and frequently require a vacuum bag cure.
Thus, there is a continuing need for ablator compositions which
1. CONFORM READILY TO THE SPACE VEHICLE BEING COATED,
2. ARE READILY REMOVABLE FROM THE SPACE VEHICLE DURING RENOVATION SUBSEQUENT TO RE-ENTRY INTO THE EARTH'S ATMOSSHERE,
3. CAN BE APPLIED IN A SMOOTH, UNIFORM WAY TO ANY DESIRED THICKNESS,
4. ARE CURABLE UNDER AMBIENT CONDITIONS OR WITHOUT REQUIRING EXPENSIVE EQUIPMENT FOR THE CURE CYCLE, AND
5. ARE INEXPENSIVE.